Dynamo-electric machine



(No Model) Hl ROBBRTSA-GHINE. AMO ELECTRIC M DYN ,1883. Patented Apr. 24

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UNITED STATES PATENT OFFICE.

HENRY ROBERTS, OF PITTSBURG, PENNSYLVANIA.

DYNAMO-ELECTRIC MACHINE.

SPECIFICATION forming part of Letters Patent No. 276,194, dated April 24, 1883.

Application iled May 4, 1382. (No model.)

To all whom it may concern Be it known that I, HENRY ROBERTS, of Pittsburg, Allegheny county, in the State of Pennsylvania, have invented certain new and useful Improvements relating to Dynamo- Electric Machines, of which the following is a specification.

The object of my invention is to cool the parts. Suppose the invention applied to a dynamo-electric machine of the style known as the Brush7 machine, the motion of the armature generates electricity, which is desired and is usefully disposed of. In addition to thatit generates heat,which is not desired, and which it is the object of my invention to dispose of. Ordinarily the heat accumulates in the parts until it reaches a temperature at which it will escape by radiation and by natural convection to the surrounding air, which is at rest, except the slight motion induced by the revolution of the armature.

It has been proposed and, I believe, attempted to cool the parts by currents of water circulated through pipes and passages in the revolvin g armature, and also in the field-magnets. Such plan is objectionable for many reasons. I have conceived and successfully reduced to practice the plan of cooling the parts by actively-circulated currents of air artificially generated for the purpose. I blow on the fieldmagnets and also on the revolving armature in sufficiently-strong blasts, and so distributed that the temperature is maintained at a low point under all conditions.

My invention contributes to the uniformity of the generation of electricity, and especially to the production of the required quantity of current with a moderate velocity ot' rotation of the armature. The uniformity of current saves the carbons of the distant lamps. The reduction of the velocity saves the brushes, and the direct cooling by the blast of air applied to the revolving armature saves this part of the apparatus, especially the spools, from the destructive eiiects of high temperature.

The following is a description of what I consider the best means of carrying out the invention.

The accompanying drawings form a part of this specification.

Figure I is a perspective view, and Fig. 2 a plan.

Similar letters of reference indicate like parts in both the gures.

The drawings represent the novel parts and so much of the ordinary parts as is necessary to indicate their relation thereto. The ordinary parts need not be described minutely.

A is the fixed framework; B, the held-magnets, and D thc revolving armature, mounted on ashaft and powerfully revolved at the proper speed by the aid of a belt (not represented) running on the pulley D. All these parts may correspond exactly with the ordinary arrangement in the Brush dynamo-machine.

M is a rotary fan-blower, driven at the rc quired high velocity by the saine power which drives the dynamo, or by any other. It receives atmospheric air at the ordinary teinperature, and blows it through a pipe, P, to the intermediate vicinity of the dynamo. Itis; represented as being led across the principal portion of the room. Other situations may servea Three branches, P P2 P3, extend from this pipe P, and lead the air in smoothly-directed currents, and direct them upon the parts liable to be heated. One pipe, P', blows the air upon the revolving armature D in the radial direction. Another branch, P2, leads the current down between the helices O, and projects the current or" air against the revolving armature in a direction nearly or quite parallel to the axis. The third, P3, correspondingly directs a blast against the opposite side oi' the armature D. The streams projected by the branches P2 and P3 should not be in the same line, but in lines parallel to each other in opposite directions, as indicated in Fig. 2.

Modifications may be made in the details.

The invention may be applied to other dynamo-machines than thoseoftheBrush pattern.

The pipe P maybe convenient-ly placed overhead, as shown, when the mechanism is already completed and in place, but for new machinery the pipes may be beneath the floor, the branches P P2 P3 coming up throughthe bed-plate in suitable positions to blow, substantially as shown.

Parts of the invention may be used without the whole.

I claim as my invention- I. The combination, with a dynamo-electric machine, of a blowing-machine, M, and pro- IOO visions for directing one or more currents of In testimony whereof I have hereunto set air therefrom upon the parts which are likely my hand, at Pittsburg, Pennsylvania, this 1st to he heated, and which are uninclosed,wliere clay of May, 1882, in the presence of two sub by the heated zur is allowed to escape freely Scribing witnesses.

5 in all directions from the heated surfaces, suh- 1 7' Y stantially as herein specified. HhNR ROBERTS' 2. llhe revolving armature D,ieldn1agnets Witnesses: B, with their helices C, blastnozzles P P2133, H.. E. HOLMES, trunk-pipe l?, and blower M, combined and ar- J. C. BRADY.

1o ranged for jointoperation, es herein specified. 

